No one I know would be interesting in accepting someone else's jewelry/gold/diamonds/platinum/silver in exchange for their food at the super market or a day's w

No one I know would be interesting in accepting someone else's jewelry/gold/diamonds/platinum/silver in exchange for their food at the super market or a day's worth of work. The goal of a currency backed by a standard is to give it a predictable and concrete exchange value. Things susceptible to speculative price fluctuations would be less then ideal. There is a self fulfilling prophecy for people who "believe" in gold and diamonds that attribute a higher value to it than the practical value or worth in industrial applications.